They can extend the length but you need to be careful and not exceed wattage per connector and cable. Also the longer the connection the less watts its safe to send down a cable. Wire size vs wattage is a hard science. Pulling too much is a good way to damage cables, gear, or invite 🔥. I would suggest short extension vs long … 4 inch (10 CM) extensions are available.
But every connection is one more place prone to fail so fewer are better.
PCIe extension cables are mostly 15-20 centimeters long.
Of course, it is better to do without adapters and extension cords, because these are additional places for control and most burnouts occur in these places. I did not have any fires, but the contacts burned out, and I noticed this only after disassembling the mining farm in search of faults.
Yeah, funny thing also, ive noticed the 8 pin connector going into the PSU was all blackened and when i touched it, it just crumbled like a dry cookie, then ive remembered i had one 3060ti riser fed by a SATA cable a while ago. Still thanking to whoever was watching over it all, because ive probably avoided burning down the whole farm and even more than that..
Probably for the best we started talking wattage and gauge, newbies who come across this might find something useful, for example, NEVER USE SATA to power GPUS or even risers, cause its not able to carry through the needed amount of watt and if overclock kicks in a reset and your GPU will demand more because its not being undervolted anymore, outcome would be really sad.
I use SATA raisers for video cards like 5600 хт, 1060, 470 and the like. But I do this only on high-quality power supplies and connect the plug directly to the raiser.
You are right that you do not need to use a SATA raiser for video cards such as RTX 3080.
For powerful video cards, as a rule, server power supplies with the required number of connectors are used.